Autodetect number of instances

Change-Id: I8137986d9c0933b6e5046b0abaf3e6f2f1059959
Partially-Implements: blueprint multinode

kolla_mesos/tests/fakes/mesos.py

@@ -0,0 +1,53 @@
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import functools
+
+import requests_mock
+
+
+MESOS_STATE = {
+    'slaves': [
+        {'attributes': {'openstack_role': 'controller'}},
+        {'attributes': {'openstack_role': 'controller'}},
+        {'attributes': {'openstack_role': 'controller'}},
+        {'attributes': {'openstack_role': 'compute'}},
+        {'attributes': {'openstack_role': 'compute'}},
+        {'attributes': {'openstack_role': 'storage'}},
+        {'attributes': {'openstack_role': 'storage'}}
+    ]
+}
+
+
+class FakeMesosStateSlaves(object):
+    """Contextmanager and decorator for mocking Mesos API Response.
+
+    This response provides a list of slaves for testing the logic about
+    counting the OpenStack nodes.
+    """
+
+    def __init__(self):
+        self.mocker = requests_mock.mocker.Mocker()
+
+    def __enter__(self):
+        self.mocker.start()
+        self.mocker.get('http://127.0.0.1:5050/state.json', json=MESOS_STATE)
+
+    def __exit__(self, *args):
+        self.mocker.stop()
+
+    def __call__(self, f):
+        @functools.wraps(f)
+        def wrapper(*args, **kwargs):
+            with self:
+                return f(*args, **kwargs)
+        return wrapper